Electrothermal heating has become an effective choice for airfoil and structure deicer heaters, especially when composite materials are used for the airfoils and/or other structures being deiced. An electrothermal heater may be used wherever icing conditions exist, including applications such as: airfoil leading edges of wings, tails, propellers, and helicopter rotor blades; engine inlets; struts; guide vanes; fairings; elevators; ships; towers; wind turbine blades; and the like, for example. In electro-thermal deicing systems, heat energy is typically applied to the surface of the airfoil or structure through a metallic heating element via electrical power supplied by aircraft or appropriate application generators. Typical heating elements are made from foil, wire, or metallic-coated fabrics.
Generally, the electro-thermal heater deicers may be implemented in a conductive pattern over or under the skin of the airfoil or other structure, or embedded in the composite material itself. The electrothermal deicer pattern, being conductive, has a tendency to give off a larger than desired cross-sectional radar image in response to radar illumination. This has become a particular problem when such deicer heater patterns are applied to military aircraft that may be illuminated by enemy radar systems. Accordingly, it is desired to keep the radar cross-section of an aircraft as small as possible.